Processes for preparing glyceraldehyde and acetals or hemiacetals thereof are known. Commonly, glyceraldehyde is made from acrolein or its acetal. In U.S. Pat. No. 2,947,761 a process for preparing glyceraldehyde is disclosed. This process makes use of acrolein as starting material, which is subjected to an epoxidation with hydrogen peroxide followed by ring opening. However, this method suffers from a number of drawbacks. In particular, hydrogen peroxide is a strong oxidizing agent which can transform the carbonyl group of acrolein into a carboxylic acid group, which leads to considerable amounts of side products. A further disadvantage of this method is that great care must be taken to maintain a constant pH level during the epoxidation reaction.
The instant invention has for its object to provide a simple method without the above-mentioned drawbacks.